The attack left blackened and smouldering wreckage, along with bodies and luggage, strewn across a wide area. Footage posted on YouTube showed a fireball erupting from the ground and a massive pall of black smoke hanging over the site of the crash.

Many of those on board the plane were due to catch connecting flights to Australia, including around 100 delegates heading to next week's international AIDS conference in Melbourne.

Prime Minister Tony Abbott says "Russian-backed rebels" appear to be to blame for the shooting down on what he has called "a grim day for our country and a grim day for our world".

"This looks less like an accident than a crime," he said in a sombre speech to Parliament.

"The bullying of small countries by big ones, the trampling of justice and decency in the pursuit of national aggrandisement, and reckless indifference to human life should have no place in our world."

Australian officials are seeking to get access to the crash site and a DFAT team is being sent to Ukraine's capital Kiev.

The United Nations Security Council is due to meet later today and Mr Abbott said Australia would be pushing for a binding resolution calling for a "full and impartial investigation" with full access to the site, the debris, the black box, and "all individuals who might be in a position to shed light on this terrible event".

US president Barack Obama joined stunned world leaders in calling for a "credible and unimpeded" international inquiry to determine the causes of a disaster which has the potential to further fan the flames of the worst East-West crisis since the Cold War.

Nationalities of MH17 passengers

Netherlands: 189*

Malaysia: 44 (including 15 crew)

Australia: 28**

Indonesia: 12 (including 1 infant)

UK: 9

Germany: 4

Belgium: 4

Philippines: 3

Canada: 1

New Zealand: 1

Unverified: 3

*N.B. One victim was a dual US citizen**N.B. DFAT says 28 Australians were on board; Malaysia Airlines says 27 Australians were on board

Source: Malaysia Airlines

"We urge all concerned - Russia, the pro-Russian separatists and Ukraine - to support an immediate ceasefire in order to ensure safe and unfettered access to the crash site for international investigators and in order to facilitate the recovery of remains," a White House spokesman said.

Ukraine's government blamed pro-Russian separatists for the attack, saying the plane had been shot down by a Buk medium range surface-to-air missile.

Russian president Vladimir Putin, who is due to visit Australia for the G20 summit in November, said the blame for the incident ultimately lay with Ukraine.

"This tragedy would not have happened if there was peace in the country, if military operations had not resumed in the south-east of Ukraine," he said.

The Russian leader said he had ordered military officials to "provide all aid needed to shed light on this criminal act."